James Comey's surprise announcement that investigators are examining new evidence in the probe of Hillary Clinton's email server put the FBI director back under a harsh spotlight, reigniting criticism of his unusual decision to discuss the high-profile case in front of the media and two congressional committees.

Comey's former colleagues said his public appearances last summer may have left the director feeling he had no choice but to let the public know when new information possibly relevant to the case arose — in this instance, according to a U.S. official, emails obtained during an investigation into allegations that former Rep. Anthony Weiner (D-N.Y.) exchanged sexually explicit messages with an underage girl.

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Some former prosecutors and Justice Department officials said the stir caused by the letter Comey sent Congress Friday announcing the FBI was examining new evidence relevant to the Clinton probe underscored the risks he took when he parted with the usual practice by publicly defending and explaining the FBI's work on the case, even though no charges were filed.

"I got a lot of respect for Jim Comey, but I don't understand this idea of dropping this bombshell which could be a big dud," said former federal prosector Peter Zeidenberg, a veteran of politically sensitive investigations. "Doing it in the last week or 10 days of a presidential election without more information, I don't think that he should because how does it inform a voter? It just invites speculation ... I would question the timing of it. It's not going to get done in a week."

Nick Akerman, a former assistant U.S. attorney in the Southern District of New York, was more critical: "Director Comey acted totally inappropriately. He had no business writing to Congress about supposed new emails that neither he nor anyone in the FBI has ever reviewed.”

"It is not the function of the FBI director to be making public pronouncements about an investigation, never mind about an investigation based on evidence that he acknowledges may not be significant," Akerman added. "The job of the FBI is simply to investigate and to provide the results of its investigation to the prosecutorial arm of the U.S. Department of Justice. His job is not to give a running commentary about any investigation or his opinion about any investigation. This is particularly egregious since Secretary Clinton has no way to respond to what amounts to nebulous and speculative innuendo.”

That was also a theme of a former Justice Department and former Democratic Senatorial Campaign Committee spokesman Matthew Miller.

“The Justice Department’s longstanding practice is don’t do anything seen as trying to influence an election. That’s usually interpreted as 60 days, let alone 11. ... It’s completely unfair to Secretary Clinton and it’s really unfair to the voters. There’s no reason he had to send this letter,” Miller told POLITICO.

Comey's July "press conference was the original sin, & it begat the rest," Miller added on Twitter.

Another former Justice official said Comey's letter could be part of an effort on his part to quiet internal FBI critics who viewed him as burying the Clinton probe for political reasons.

“He’s come under a lot of criticism from his own people for how he’s handled this. He’s trying to gain back some of their respect,” former Justice Department spokeswoman Emily Pierce said. “His ability to do what he does largely depends on the respect within his own ranks. He often does things because he’s trying to prove his bona fides to his rank and file. I think that’s part of it.”

The latest move in the Clinton email saga comes at the same time federal law enforcement is examining the suspected Russian hacking of U.S. political operatives, including the Democratic National Committee and Clinton campaign chairman John Podesta. Democrats are also pushing for the FBI to take a closer look as they do those probes into the connections between Russia, the release by WikiLeaks of Podesta's stolen emails and several operatives who have worked for and around the Trump's campaign.

Several current and former DOJ, FBI and intelligence community sources earlier this month told POLITICO they have little doubt that federal law enforcement was looking into all of those questions. And on Twitter, Miller wrote that while the FBI “is undoubtedly investigating” those links, it was doing the right thing by staying mum on the matter.

“They shouldn’t be commenting on investigations! But that should apply to all. Instead, Clinton consistently treated differently/worse,” the former Obama DOJ spokesman added.

Comey defenders said his actions undoubtedly were part of an effort by him to remain above politics.

“After being roasted from both sides, but even without that, the director’s approach is to just keep your head down and do what one normally does. When something you’ve said needs to be clarified and might have changed, you do it. It might not always be a convenient time, but you don’t calculate," said Columbia law school professor Dan Richman, a former federal prosecutor.

“The last thing anybody wants to do is have the organization sit on something where Congress has shown such particular interest," Richman added. “There’s no winning this game, and one of the clearest things the director has been on so far is, he’s trying not to play the game and to keep his head down."

Some said the FBI's move was likely designed to avoid second-guessing later, but highly unlikely to change the decision not to seek charges in the case.

"To me, it's probably someone covering their butt so they don't look bad if they sat on it," Zeidenberg said. "They said [Clinton] was 'careless' before, what about that is going to change? Let's say there's one more [classified email] how does that change anything? Now, politically, that's a whole different story."

Others said they suspected the new information was significant, drawing that conclusion from the fact that Comey sent a letter advising congressional committee chairs of the new information.

"Why would FBI reopen Hillary investigation unless there is evidence of more than 'extreme carelessness' in handling classified information?" Republican Sen. John Cornyn, a former Texas attorney general, wrote on Twitter.

Some former FBI officials agreed, saying it was inconceivable to them that Comey would announce such a development because of some incremental or cumulative information in such a high-wattage case.

"It never happens," said one former FBI official, who asked not to be named. "Once you vacate a high-profile case, unless there's some very significant omission, they won't [reopen] it."

The source also said he doubted Comey would call attention to something that was minor.

"Comey's not that way. He's a very practical man. It must be something that goes to the substance," the ex-agent said. "It can't be cumulative. He's not a grandstander... It's not his style."

Another former high-ranking FBI official agreed.

“The only reason he’d do it is if he had something very pertinent. Certainly, 11 days before an election it could well affect the outcome. It just doesn’t make much sense without something very substantive,” the ex-official said.

One answer to the puzzling development could also lie in the way the Clinton email probe began: as a referral from intelligence agencies about a potential loss of classified information.

If information likely to be classified was found on Weiner's devices or in his accounts, possibly transferred from his wife, the FBI would have a duty to confirm its classification and explore whether the information was compromised. Comey may have decided that, despite the media and political attention, the most logical way to carry out that assessment was using the same agents and contacts developed in the Clinton email probe.

Abedin told FBI investigators earlier this year that she used an official State Department email account, one on Clinton's server and another related to campaign activities of her husband, Anthony Weiner.

Comey, who enjoyed widespread bipartisan support as a law-and-order figure before announcing the outcome of the Clinton email investigation in July, was nominated as FBI Director by President Barack Obama in 2013.

FBI directors typically serve a 10-year term in an effort to put them beyond the winds of politics, but Obama had difficulty filling the slot of retiring FBI Director Robert Mueller in 2011. The White House eventually persuaded Mueller to accept a two-year extension, which required congressional approval.

As Mueller’s extended term ran out, the White House settled on Comey.

Comey was at one point a registered Republican and he served as deputy GOP counsel to the Senate Whitewater Committee in 1996, when it investigated the land investment of Hillary Clinton and her husband — then-Gov. Bill Clinton —entered into before he was elected to the White House.

Later, as the powerful U.S. attorney for the Southern District of New York during the George W. Bush administration, Comey oversaw the tail end of an investigation into Bill Clinton’s pardon of fugitive billionaire Marc Rich. No charges were ever filed in that case, nor was there a public explanation of the office’s findings.

Comey won the respect of many Democrats over actions he took after assuming the No. 2 position at the Justice Department in late 2003. While the story did not emerge for years, Comey took part in a showdown with White House officials over an extension of surveillance program instituted after the Sept. 11, 2001 attacks.

Comey became convinced it wasn’t legal and refused to sign paperwork reauthorizing the program. The episode led to a bizarre bedside confrontation where White House Counsel Alberto Gonzales and chief of staff Andy Card tried to get a hospitalized and heavily medicated Attorney General John Ashcroft to sign off.

Ashcroft also refused to sign, leaving Bush in the position of having to act without Justice Department approval or halt the program while it was redesigned. He chose the latter. The episode guaranteed Comey a place in Washington legal lore and helped make him a popular choice for FBI director. He was confirmed by the Senate in July 2013 in a vote of 93-1.

During a Congressional appearance last month, Comey himself acknowledged that there is legitimate debate over his decision to speak out publicly about the Clinton email probe, but he urged people not to allow that discussion to cast a shadow over the FBI's integrity.

"I think questions are fair. I think criticism is healthy and fair. I think reasonable people can disagree about whether I should have announced and how I should have done it," the FBI director said. "What's not fair is any implication the bureau acted in any way other than independently, competently and honestly here."